Vaccination of mice against H pylori induces a strong Th-17 response and immunity that is neutrophil dependent.
OBJECTIVE
Vaccine efficacy against gastric Helicobacter pylori infection has been shown in mice, but little is known about the mechanisms of bacterial clearance. Our aim was to investigate a possible T-cell/neutrophil pathway of vaccine-induced protection.


METHODS
Nonimmune and immunized mice were compared for their response to H pylori challenge. T-cell responses were assessed by recall assays. Interleukin (IL)-17-induced chemokine production was evaluated by cytokine enzyme-linked immunosorbent assay. In a kinetic study, biopsy specimens were collected at multiple time points postchallenge and assessed for bacterial load and inflammation. Relative levels of T cells, IL-17, interferon gamma, MIP-2, KC, and LIX were determined by quantitative polymerase chain reaction. The role of neutrophils was evaluated by antibody-mediated depletion of neutrophils following challenge.


RESULTS
Immunization induced strong interferon gamma- and IL-17-producing T-cell responses, and IL-17 was capable of inducing significant amounts of KC and MIP-2 from dendritic cells, macrophages, fibroblasts, and gastric epithelial cells. Challenge of immunized mice induced significantly greater gastritis than that of infected mice, preceding significantly lower bacterial loads by day 7. In immune mice, T-cell recruitment to the gastric mucosa correlated with a continuous rise in IL-17 and interferon gamma levels, followed by KC, MIP-2, and LIX production and the recruitment of significant numbers of neutrophils by day 5. Antibody-mediated depletion of neutrophils abrogated vaccine efficacy.


CONCLUSIONS
Vaccination of mice against H pylori results in a significant Th-17 cell recall response associated with increases in chemokines that attract neutrophils to the stomach, which are important for eradication of H pylori.
DeLyria
Elizabeth S
ES
Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Redline
Raymond W
RW
Blanchard
Thomas G
TG
D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002465:Cell Movement; D018925:Chemokines / Q000096:biosynthesis; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology / Q000382:microbiology; D016179:Granulocyte Colony-Stimulating Factor / Q000502:physiology; D016480:Helicobacter pylori / Q000276:immunology*; D007249:Inflammation / Q000209:etiology; D020381:Interleukin-17 / Q000096:biosynthesis*; D008407:Mast Cells / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000502:physiology*; D014611:Vaccination
D001428:Bacterial Vaccines; D018925:Chemokines; D020381:Interleukin-17; D016179:Granulocyte Colony-Stimulating Factor